class JustTesting : public Gtk::Window {
public:
    JustTesting():  btn("Hi") {
        set_title("Just Testing");
        set_border_width(10);

        btn.signal_clicked().connect(sigc::mem_fun(*this, &JustTesting::on_button_clicked));

        add(btn);

        show_all();
    }

    ~JustTesting() {}

protected:
    //Signal handlers:
    void on_button_clicked() {
        Gtk::MessageDialog dialog(*this, "Just testing...",false, Gtk::MESSAGE_INFO,Gtk::BUTTONS_OK);
        dialog.run();
    }

    //Member widgets:
    Gtk::Button btn;
};
